Volume control unit



FIG. 1 is a front view of a volume control unit showing my new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a perspective view thereof.

In the drawings, the broken lines depict environmental subject matter only and form no part of the claimed design. 

The ornamental design for a volume control unit, as shown and described. 